Prior to this invention, van-type vehicles have been specially manufactured to transport prisoners or to protect passengers against outsiders. Frequently, however, such specially constructed vehicles are not available or readily obtainable or do not have sufficient capacity to handle different situations such as the transportation of prisoners from a battle zone, the transportation of detained rioters from a disturbed area, or the transportation of armed service personnel or security personnel (such as police) in dangerous areas. Make-shift constructions to meet emergency conditions usually are inadequate to meet the needs arising from the types of situations mentioned above. Furthermore, vans which are permanently and specially constructed to meet security needs, are not versatile primarily because the security enclosure cannot be dissembled or removed.